Metal product manufacturing device and metal product manufacturing method

ABSTRACT

A metal product manufacturing device is provided to remove, with higher accuracy, impurities from a molten metal of a non-ferrous metal or another metal containing the impurities, obtain the molten metal having higher purity, and obtain a high-purity non-metal product or another metal product from the high-purity molten metal.

TECHNICAL FIELD

The present invention relates to a metal product manufacturing deviceand a metal product manufacturing method.

BACKGROUND ART

Conventionally, a product of a non-ferrous metal or a product of anothermetal is produced by performing casting with a molten metal having aconductive property (conductivity), that is, a molten metal of anon-ferrous metal (for example, Al, Cu, Zn, Si, an alloy of at least twoof these, an Mg alloy, or the like) or a molten metal of another metalother than the non-ferrous metal. As an initial process out of suchprocesses, there are processes of melting and quality governing. Inrecent years, due to development in a recycle technology and increase inawareness of environmental conservation, scrap is also increasinglyreused. However, there is a problem that impurities are contained in ametal obtained from the scrap. In other words, first of all, impuritiesare originally contained inside the scrap as a raw material.Additionally, the impurities are generated at the time of melting workof the scrap and are dissolved inside a molten metal. Therefore, it isinevitable that the impurities are contained inside the molten metalobtained by recycling the scrap. When a product of a non-ferrous metalor a product of another metal is produced from such a molten metal, theproduct results in containing impurities, and quality and performance ofthe product may be degraded. From this point, it is extremely importantto remove impurities from a molten metal that uses the scrap as the rawmaterial. Therefore, conventionally, the impurities are removed from themolten metal by various methods. For example, a filter is used tofiltrate and remove the impurities contained inside the molten metal.Furthermore, flux is charged, or gas is blown into the molten metal tochange the impurities into a compound, and the compound is made to floaton a surface of the molten metal and then removed. Moreover, after theimpurities are removed from the molten metal by the flux or the gas, theimpurities are further removed from the molten metal by using a filter.

SUMMARY OF INVENTION Technical Problem

As described above, conventionally, there is a method of using a filteras a method of removing impurities from a molten metal. However, thefilter is instantly clogged and required to be replaced with a new oneshortly. Additionally, to remove finer impurities, it is necessary to:prepare a plurality of filters having different mesh sizes; remove firstthe impurities by using a filter having a large mesh size, and nextremove the impurities by using a mesh size smaller than the previousfilter, respectively; and repeat this removal of the impurities multipletimes by sequentially using filters having smaller mesh sizes. However,performing such filtration work multiple times by using the filtershaving the different mesh sizes in order to remove the impurities isactually very troublesome, takes a long time, and leads to increase inoperation costs. Also, there is a limit in downsizing a mesh size of afilter, and the mesh size can be downsized only to some extent.Furthermore, the filters are extremely expensive. From such viewpoints,performing the impurity removal work with the filters has problems onwhether or not the impurities can be removed, and in the cost and otheraspects.

Additionally, the impurities can also be removed from the molten metalto some extent by the method of using flux or gas as described above.However, even with this method, the impurities cannot be removedsufficiently. Furthermore, the impurities inside the molten metal cannotbe removed sufficiently even by further filtrating, with a filter, themolten metal from which the impurities have been removed by using theflux or the gas.

Thus, conventionally, it has been actually very difficult to obtain ahigh-purity molten metal despite a fact that attempts have been made toremove impurities from a molten metal of a non-ferrous metal or a moltenmetal of another metal obtained from scrap or the like and containingthe impurities. Therefore, it is actually not possible to obtain ahighly-purity metal product from the molten metal obtained from thescrap or the like. In other words, a metal product required to have highpurity is needed to be produced not from the scrap or the like but froma molten metal obtained from a primarily high-purity raw material.Therefore, a high-purity product of a non-metal or a high-purity productof another metal is inevitably expensive. Therefore, conventionally,those skilled in the art found it impossible to remove impuritiessufficiently from a recycled molten metal, and gave up on producing ahigh-purity product from the recycled molten metal from the very start.However, the present inventor questioned about this point and hascontinued his unique study and research in order to find a method ofremoving a larger amount of impurities from the recycled molten metal orthe like and obtaining a high-purity molten metal, without giving up onusing the recycled molten metal or the like.

The present invention is uniquely achieved by the present inventor onthe basis of the above-described inventor's unique awareness of theproblems, and an object of the present invention is to provide a deviceand a method capable of: removing impurities, with higher accuracy, froma molten metal of a non-ferrous metal or a molten metal of another metalcontaining the impurities; obtaining a molten metal having higherpurity; and obtaining a high-purity non-metal product or another metalproduct from the high-purity molten metal.

Note that the present inventor has previously disclosed, in JapanesePatent Nos. 5,669,504 and 5,431,438, the inventions different from thepresent invention. The technical ideas described in these publicationsare directed to improving product quality more by rotationally driving amolten metal with large stirring force as quickly and surely aspossible, but are not directed to removing impurities from the moltenmetal. Accordingly, the present invention is a different inventionhaving the technical idea completely different from and unrelated to theinventions of the above-described publications, and is not conceivablefrom the inventions of the above-described publications.

Solution to Problem

An embodiment of the present invention is

a metal product manufacturing device including a container that stores amolten metal having a conductive property, the metal productmanufacturing device including:

a cylindrical container body portion;

an upper end plate and a lower end plate that close both ends of thecontainer body portion in a sealed state;

an upper electrode fixed to the upper end plate in a state of passingthrough the upper end plate, and having an inner end electricallyconnectable to the molten metal; and

a lower electrode fixed to the lower end plate in a state of passingthrough the lower end plate, and having an inner end electricallyconnectable to the molten metal, in which

at least the upper end plate is detachable from the container bodyportion,

the upper electrode is fixed to a substantially central portion of theupper end plate in the state of passing through the upper end plate in athickness direction,

the lower electrode is fixed to a substantially central portion of thelower end plate in the state of passing through the lower end plate in athickness direction, and

the upper electrode and the lower electrode are located on asubstantially vertical straight line in an upper-lower direction.

Furthermore, an embodiment of the present invention is

a metal product manufacturing method of manufacturing a metal productfrom a molten metal having a conductive property, the metal productmanufacturing method including:

preparing a container that includes:

a cylindrical container body portion;

an upper end plate and a lower end plate that close both ends of thecontainer body portion in a sealed state;

an upper electrode fixed to the upper end plate in a state of passingthrough the upper end plate, and having an inner end electricallyconnectable to the molten metal; and

a lower electrode fixed to the lower end plate in a state of passingthrough the lower end plate, and having an inner end electricallyconnectable to the molten metal, in which

at least the upper end plate is detachable from the container bodyportion,

the upper electrode is fixed to a substantially central portion of theupper end plate in the state of passing through the upper end plate in athickness direction,

the lower electrode is fixed to a substantially central portion of thelower end plate in the state of passing through the lower end plate in athickness direction, and

the upper electrode and the lower electrode are located on a straightline in an upper-lower direction;

making the metal having the conductive property and stored inside thecontainer into a state of a molten metal while the container is sealedby the upper end plate and the lower end plate;

electrically connecting the inner ends of the pair of electrodes to themolten metal having the conductive property; and

applying a current between the pair of electrodes in this state.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic entire configuration diagram of a metal productmanufacturing device used to implement the present invention.

FIG. 1A is a schematic explanatory view illustrating a form of an actualuse state of the device in FIG. 1.

FIG. 2 is an explanatory plan view of a container and a magnetic fielddevice in FIG. 1.

FIG. 3 is an explanatory cross-sectional view taken along a line III-IIIin FIG. 1.

FIG. 4 is an explanatory plan view of the magnetic field device in FIG.1.

FIG. 5 is an explanatory plan view illustrating a modified example inFIG. 4.

FIG. 6 is an explanatory longitudinal sectional view of the container inFIG. 1.

FIG. 7 is an explanatory plan view of the container in FIG. 1.

FIG. 8 is an explanatory view of a separated state of a container bodyand an end plate in FIG. 6.

FIG. 9 is an explanatory view illustrating density of a current flowingbetween a pair of electrodes via a molten metal.

FIG. 10 is an explanatory view to describe the density of the current inFIG. 9.

FIG. 11 is an explanatory view illustrating a magnetic field generatedin the case of FIG. 9.

FIG. 12 is an explanatory view illustrating Lorentz force generated inthe case of FIG. 9.

FIG. 13 is an explanatory view illustrating a pressure gradientgenerated inside the molten metal in the case of FIG. 9.

FIG. 14 is a cross-sectional explanatory view illustrating adistribution state of impurities in a product obtained in the case ofFIG. 9.

FIG. 15 is an explanatory view illustrating density of a current in acase of applying the current upward from below contrary to the case ofFIG. 9.

FIG. 16 is an explanatory view illustrating the density of the currentin FIG. 15.

FIG. 17 is an explanatory view illustrating a magnetic field generatedin the case of FIG. 15.

FIG. 18 is an explanatory view illustrating Lorentz force generated inthe case of FIG. 9.

FIG. 19 is an explanatory view illustrating one mode of use in FIG. 1and also is the explanatory view in a case of applying a currentdownward in a state of applying a magnetic field.

FIG. 20 is an explanatory view illustrating electromagnetic force(Lorentz force) generated in the case of FIG. 19.

FIG. 21 is an explanatory view of electromagnetic force in a case ofapplying the current upward in a direction opposite to the case of FIG.19.

FIG. 22 is an end surface view of a product obtained by implementing thepresent invention.

FIG. 23 is an end surface view of a product obtained under conditionsdifferent from those of FIG. 22.

FIG. 24 is an end surface view of a product obtained under conditionsdifferent from those in FIG. 22 and the like.

FIG. 25 is an end surface view of a product obtained under conditionsdifferent from those of FIG. 22 and the like.

FIG. 26 is an end surface view of a product obtained under conditionsdifferent from those of FIG. 22 and the like.

DESCRIPTION OF EMBODIMENTS

As described above, the present invention is provided to solve theabove-described technical problem of obtaining a high-quality productfrom a molten metal containing impurities, that is, the problem uniqueto the present inventor. In other words, the present invention is basedon results of unique experiments repeatedly conducted by the presentinventor multiple times in order to solve the technical problem, and thepresent invention is hardly conceivable by other engineers who are notas proactive as the present inventor in solving the above-describedtechnical problem and have not uniquely conducted the experiments themultiple times.

The more details are as described below.

The present inventor has continued day and night the technical researchto obtain a molten metal of a non-ferrous metal or a molten metal ofanother ferrous metal having higher purity and suitable for producing ahigher quality non-metal product and another metal product. In course ofthe process, the present inventor has become uniquely eager to solve thetechnical problem of removing impurities from a recycled molten metal orthe like containing a large amount of the impurities, regarding whichother engineers have not been so proactive.

The research has been made for a long time on the basis of this, and asa result, the present inventor has reached a technical idea as follows.That is, the present inventor has noticed that, in the process of theresearch, a molten metal of a non-ferrous metal or a molten metal ofanother ferrous metal containing impurities might be grasped as aso-called multiphase fluid. In other words, the present inventor hasreached the idea that the molten metal could be grasped as themultiphase fluid including: the molten metal of the non-ferrous metal orthe molten metal of another ferrous metal as a base; and a molten metalof the impurities dissolved therein.

Furthermore, assuming that the above-described multiphase fluid is amultiphase fluid in terms of Archimedes electromagnetic force, it isfairly sure that the multiphase fluid can be theatrically grasped as:the fluid as the base: and the fluid (particles) of the impuritiesdissolved therein. Assuming that the molten metal of the non-ferrousmetal or the molten metal of another ferrous metal containing impuritiesis the multiphase fluid in terms of the Archimedes electromagneticforce, the impurities inside the molten metal of the non-ferrous metalor the molten metal of another ferrous metal can be moved by theArchimedes electromagnetic force along a pressure gradient by adding thepressure gradient to the molten metal of the non-ferrous metal or themolten metal of another ferrous metal as the base, and consequently, itis fairly sure that the impurities can be separated from the base.

However, conventionally, no prior art has disclosed a technology inwhich a molten metal containing impurities was separated by theArchimedes electromagnetic force into: a base of a non-ferrous metal oranother ferrous metal; and the impurities contained therein. This may bebecause, conventionally, those skilled in the art have never generallyconsidered the molten metal of the non-ferrous metal or another ferrousmetal containing impurities in association with the multiphase fluid interms of the Archimedes electromagnetic force. In other words,supposedly, those skilled in the art have considered that the moltenmetal of the non-ferrous metal or another ferrous metal containing theimpurities was not the multiphase fluid in terms of the Archimedeselectromagnetic force. In other words, supposedly, those skilled in theart have never considered that a molten metal could not be separatedinto a base and impurities even though the Archimedes electromagneticforce is applied to the molten metal of the non-ferrous metal or anotherferrous metal containing the impurities. Actually, there is no prior artthat discloses that a molten metal of a non-ferrous metal or anotherferrous metal containing impurities can be separated into the moltenmetal as the base and the impurities by applying the Archimedeselectromagnetic force to the molten metal, and also there is no priorart that suggests so.

The present inventor has struggled and repeatedly conducted variouskinds of experiments multiple times in order to confirm these points.The experiments were conducted not intending to separate impurities toan upper side and a lower side as conceived by a general engineer butintending to place the impurities in a periphery of a round bar or asquare bar so as to easily perform subsequent impurity removalprocessing, in a case of producing the round bar or the square bar ofthe non-ferrous metal or another ferrous metal in order to obtain aproduct having higher purity.

Consequently, products illustrated in FIGS. 24 to 26 and the like couldbe finally obtained. That is, the products in FIGS. 24 to 26 illustrateend surfaces of aluminum round bars (billets) obtained from theexperiments by the present inventor. FIGS. 21 to 26 are diagrams eachillustrating distribution of impurities (Al₃Fe) obtained from colorphotographs of the respective end surfaces of the products. Asunderstood from these diagrams, the impurities (Al₃Fe) could be gatheredat a peripheral portion of a high-purity aluminum at a center portion.

Thus, since the impurities could be gathered at the periphery instead ofat the upper and lower sides of the product, the subsequent impurityremoval processing can be performed while looking at the end surface andvisually confirming removal work of the impurities, or the subsequentimpurity removal processing can be performed after visually confirmingand learning a place of the impurities in advance, and accordingly, theimpurities can be easily and surely removed from the product.

Note that it is technically obvious that the technical idea forobtaining such products is applicable to a non-ferrous metal other thanaluminum, or to another metal.

Thus, the present inventor has discovered that, through the uniqueexperiments conducted many times by himself, the impurities can begathered at the periphery from the non-ferrous metal or another metalcontaining the impurities by using the Archimedes electromagnetic force.

As described above, the present invention is made on the basis of thediscovery achieved through the unique experiments conducted by thepresent inventor, and is the invention that can be achieved only by theinventor who has conducted the experiments and also is the inventionthat cannot be achieved by other those skilled in the art who have notconducted the experiments. Particularly, it is considered that gatheringthe impurities at the periphery of the product instead of at the upperand lower sides thereof can be achieved only by the present inventor.

Hereinafter, embodiments of the present invention will be described withreference to the drawings.

First, an outline of a metal product manufacturing device 100 of thepresent invention will be described with reference to the drawings. Notethat each of the drawings is a schematic drawing to describe the presentinvention, and a scale of a dimension in each of the drawings is not thesame, and an aspect ratio of each of members in each of the drawings canbe freely selected besides that illustrated in each of the drawings.

The metal product manufacturing device 100 includes, as illustrated inFIG. 1, a container 1, a magnetic field device 2, and a power supplydevice 3. The container 1 is provided to store a molten metal obtainedfrom, for example, a non-ferrous metal or another metal that isrecycled, includes impurities, and has a conductive property. Thenon-ferrous metal or another metal is a non-ferrous metal of a conductor(electric conductor) of Al, Cu, Zn, an alloy of at least two of these,an Mg alloy, or the like, or another metal other than the non-ferrousmetal. The container 1 is freely detachable from the device 100.Additionally, the magnetic field device 2 is also freely detachable fromthe device 100 mutually independent from the container 1.

As understood particularly from FIG. 6, the container 1 includes acylindrical container body 5 and end plates 6 and 7 that close upper andlower ends thereof, in which both the container body and the end platesare made from a refractory material. The end plates 6 and 7 are attachedto the container body 5 with pressure tightness in a manner capable ofsealing the inside of the container body 5. In other words, asunderstood from FIG. 8, at least one of the end plates 6 and 7 (theupper end plate 6 in the illustrated embodiment) is detachable from thecontainer body 5. The reason why the pressure tightness is providedbetween the container body 5 and the end plates 6 and 7 is to keep ahigh-pressure state in the inside of the container even in a case wherethe inside of the container 1 comes to have a high pressure.

A pair of electrodes (an upper electrode and a lower electrode) 8 and 9each made from an electric conductor (for example, ceramics having aconductive property, such as graphite) are substantially verticallyinstalled at the center portions (substantially central portions) of theend plates 6 and 7 in a fixed state while the electrodes respectivelypass through the end plates 6 and 7 in a thickness direction. In otherwords, the upper electrode 8 and the lower electrode 9 are located on asubstantially vertical straight line in an upper-lower direction, andface each other in the shortest distance. With this configuration, in astate where a molten metal M is stored in the container 1, the moltenmetal M inside is electrically conducted with the electrodes 8 and 9.The electrodes 8 and 9 are detachable from the end plates 6 and 7,respectively. With this configuration, the electrodes 8 and 9 each canbe replaced by another one when worn out.

The container body 5 can have various configurations such that a productP obtained by solidifying the molten metal M can be easily taken out.For example, the container body 5 can be divided into two.Alternatively, the inside thereof may be tapered.

In particular, as understood from, for example, FIG. 1 and FIG. 2 as aplan view of the device 100, the annular magnetic field device 2including a permanent magnet is arranged at an outer peripheral positionof the container body 5. In the magnetic field device 2, an N pole ofone magnet (magnet body) 2 a faces the other magnet (magnet body) 2 bsideways as understood from FIG. 4. Needless to mention, an S pole ofthe one magnet 2 a may face an N pole of the other magnet 2 b on thecontrary. The magnetic field device 2 can also include an electromagnet.

Both the container 1 and the magnetic field device 2 are detachable fromthe metal product manufacturing device 100 in a manner relativelyindependent from each other. With this configuration, for example, thecontainer 1 can be attached to or detached from the magnetic fielddevice 2 provided in a fixed state, as illustrated in the stateillustrated in FIG. 1. Alternatively, the magnetic field device 2 can bedetachably incorporated into the container 1 provided in the fixedstate.

Additionally, a magnetic field device 2A including a pair of magnetpieces 2 a 1 and 2 b 1 can also be used as illustrated in FIG. 5,instead of the integral annular magnetic field device 2 in FIG. 4. Themagnetic field device 2A can also include an electromagnet. In thiscase, polarities of the pair of magnet pieces 2 a 1 and 2 b 1 areswitched at a desired period such as 1 Hz to 10 Hz, so as to switch amagnetic force line ML between a state of running from right to left anda state of running from left to right in the drawing of FIG. 5.

As understood from FIG. 1, the electrodes 8 and 9 of the container body5 are connected to the power supply device 3 by wires 11 and 12,respectively. The wires 11 and 12 can be connected to and disconnectedfrom the electrodes 8 and 9, respectively. The power supply device 3 canapply a direct current and an alternating current. Additionally, forexample, the container 1 is relatively detachable from the magneticfield device 2 as described above. Accordingly, the container 1 can takea state incorporated into the device 100 as illustrated in FIG. 1 and astate detached from the device as illustrated in FIG. 1A. Needless tomention, the magnetic field device 2 is also detachable from the device100 as described above.

Next, an operation principle of the device 100 will be described.

In the metal product manufacturing device 100, as understood from FIGS.1 and 4, the metal product manufacturing device 100 includes themagnetic field device 2 as described later in detail. Therefore, in acase of applying a current I to the molten metal M in an operating stateof the magnetic field device 2, first Lorentz force (electromagneticforce) and second Lorentz force (electromagnetic force) act at the sametime. However, as described later, in a case where no magnetic fielddevice 2 is provided or in a case where the magnetic field device 2 isnot in the operating state, only the first Lorentz force acts asdescribed later.

That is, the first Lorentz force is electromagnetic force generated bycombination of the current I and a magnetic field based on the currentI. The second Lorentz force is electromagnetic force generated bycombination of the current I and an externally-applied magnetic field.The first Lorentz force serves as force directed toward a center of themolten metal M, this force generates a pressure gradient inside themolten metal M, Archimedes electromagnetic force acts on impuritiesinside the molten metal M, and the impurities are moved toward aperiphery of the molten metal M. The second Lorentz force is applied tothe molten metal M in a direction of laterally driving the molten metalM. In other words, combination of the current I flowing inside themolten metal M with the magnetic field from the magnetic field device 2generates the second Lorentz force, and this second Lorentz force isapplied to the molten metal M.

Hereinafter, the principle of the metal product manufacturing device 100will be described more in detail.

Now, as understood from FIG. 6, assume that the molten metal M of anon-ferrous metal or a ferrous metal is stored inside the container 1,and in this state, the current I is applied from the upper electrode 8to the lower electrode 9 via the molten metal M in a downward directionin FIG. 9. FIG. 9 is a side view and FIG. 10 is a plan view, and bothschematically illustrate density distribution of the current I at thistime. This current distribution is obtained from findings obtained bythe present inventor on the basis of his long-time experience in the artof the technical field of the present invention. At the same time, areason why this current distribution is technically correct is supportedby a fact that the products illustrated in FIGS. 24 to 26 are obtainedas described above according to the present invention. Thus, in themolten metal M, the current density becomes high near the electrodes 8and 9, and the current density becomes low at positions away from theelectrodes 8 and 9. Note that, in these FIGS. 9 and 10, the current Iflowing between the pair of electrodes 8 and 9 via the molten metal M isillustrated in a coarse/dense state for easy visual understanding, whiledeeming the current I as a group of a plurality of unitary currents Iu.

Then, a magnetized field (magnetic field) having a magnitude accordingto the Biot-Savart law is generated around each of the unitary currentsIu. Consequently, a magnetized field generated by a certain unitarycurrent Iu is combined with another unitary current Iu. For example, inFIG. 10, a magnetized field generated by a certain unitary current Iu(1) is combined with another unitary current Iu (2). This is universallytrue for all of the unitary currents Iu. With such combination, theLorentz force f (first Lorentz force) illustrated in FIG. 12 isgenerated as described later.

Note that, from a different viewpoint, all of the magnetized fields ofthe respective unitary currents Iu are synthesized, and a synthesizedmagnetic field including magnetic force lines ML is generated asillustrated in FIG. 11. As understood also from FIG. 11, a direction ofthe magnetized field in this synthesized magnetic field is clockwisefrom the top view. As for the density of this magnetic field, asillustrated in FIG. 11, a center part has high density and the densitybecomes gradually lower as the position approaches the periphery in thetop view. As described above, this magnetic field is combined with thecurrent I (respective unitary currents Iu). With this combination, asillustrated in FIG. 12, the Lorentz force f (first Lorentz force)directed toward the center is generated in the molten metal M of thenon-ferrous metal or the current density metal as a base. This Lorentzforce is the force that pushes the non-ferrous metal or another metaltoward the center part. In other words, in the molten metal M of thenon-ferrous metal or the molten metal M of another metal, a pressuregradient in which a pressure is high on the center side and a pressureis low on the periphery side is generated. One example of this pressuregradient is illustrated in FIG. 13. As understood from FIG. 13, pressureP is higher at a center C than at a periphery P. Due to this pressuregradient, impurities contained inside the molten metal of thenon-ferrous metal or another metal are pushed toward the periphery. As aresult, the impurities are moved to a peripheral portion PP asillustrated in FIG. 14 and made into an accumulated state, and animpurity concentration in an inner portion IP is significantlydecreased, and the inner portion is to have a non-ferrous metal oranother metal having high purity. Here, a non-ferrous metal product oranother metal product having high purity can be obtained by removing thenon-ferrous metal or another metal having the high impurityconcentration at the peripheral portion PP by a desired method.

Note that, in the above description, the case of applying the current Idownward from above in the drawing is assumed in FIG. 9, but the currentI can also be applied upward from below in the opposite direction asillustrated in FIG. 15. In this case also, a pressure gradient has highpressure on the center side and has low pressure on the periphery in amanner similar to the above-described case. Accordingly, the impuritiesare gathered at the peripheral portion of the product, similar to FIG.14. Note that FIGS. 16 to 18 are explanatory views corresponding toFIGS. 10 to 12.

Additionally, an alternating current can also be applied between thepair of electrodes 8 and 9. In this case, as understood from the abovedescription, the Archimedes electromagnetic force applied to theimpurities is not changed from the case of applying the direct currentin any of the directions, and the impurities are gathered at theperipheral portion of the product by the Archimedes electromagneticforce.

Additionally, when the current I is applied between the pair ofelectrodes 8 and 9, the current I is combined with the magnetic fieldfrom the magnetic field device 2. Consequently, the second Lorentz forceis generated.

That is, referring to FIGS. 19 and 20, assume that the current I isapplied downward in the drawing like this FIG. 19. Consequently, thecurrent I is combined with the magnetic force lines ML from the magneticfield device 2, and streams of the second Lorentz force (F11 and F21)(FIG. 20) are generated. Alternatively, assume that the current I isapplied upward from below in FIG. 19. In this case also, streams of thesecond Lorentz force (F12 and F22) are generated similar to the casewhere the current flows downward from above, but the directions thereofare opposite. Alternatively, in a case of applying the alternatingcurrent as the current I, the Lorentz force (second Lorentz force)caused by combination of the current I with the magnetic field from themagnetic field device 2 is reversed in accordance with a period of thealternating current. In other words, the streams of the Lorentz force(second Lorentz force) F11 and F22 acting in the directions asillustrated in FIG. 20 and the streams of the Lorentz force (secondLorentz force) 12 and F22 acting in the direction as illustrated in FIG.21 are alternately applied to the molten metal M

This will be described more in detail with reference to FIGS. 19 to 21.In FIG. 19, consider the case where the current I flows downward in thedrawing. In this case, the magnetic force lines ML are directed fromright to left in the drawing as illustrated in FIG. 19. Consequently,the current I (respective unitary currents Iu) and the magnetic forcelines ML are combined, and the streams of the electromagnetic force(second Lorentz force) F11 and F21 are generated as illustrated in FIG.20. Also, in the case of applying the current directed upward from belowas the current I in FIG. 19, the streams of the electromagnetic force(second Lorentz force) F12 and F22 are generated as illustrated in FIG.21. Accordingly, in the case of applying the alternating current as thecurrent I (for example, 1 to 10 Hz or the like), the molten metal isapplied with the streams of the electromagnetic force F11 and F21 andstreams of the electromagnetic force F11 and F21 which are alternatelydirected in the opposite directions in accordance with the period of theapplied current I. Consequently, micro-vibration is caused in the moltenmetal M. Since such micro-vibration is added to the molten metal M,accumulation of the impurities is accelerated at the peripheral portionPP of the product by the Archimedes electromagnetic force as illustratedin FIG. 14 in the process of changing the molten metal from a liquidphase state to a solid phase state by cooling, and finally, the productP as illustrated in FIG. 14 can be obtained.

In this product P, a metal product with high accuracy can be obtainedwhen the impurities IM at the peripheral portion PP are removed by adesired method. As described above, the impurities are accumulated atthe periphery of the product P and can be easily visually grasped, andtherefore, removal work of the impurities can be easily and surelyperformed, and the product P of the non-ferrous metal or another metalcan be surely obtained with higher accuracy.

As understood from the above description, the metal productmanufacturing device 100 of the present invention can adopt variousconfigurations and various modes of use. For example, the followingmodes can also be adopted.

(a) In FIG. 1, the magnetic field device 2 manufactured from thepermanent magnet is detached or the magnetic field device 2 manufacturedfrom the electromagnet is set to the non-operating state, and in thisstate, the direct current or the alternating current is applied as thecurrent I between the electrodes 8 and 9.

(b) In FIG. 1, the magnetic field device 2 manufactured from thepermanent magnet is installed, or the magnetic field device 2manufactured from the electromagnet is set to the operating state, andin this state, the direct current or the alternating current is appliedas the current I between the electrodes 8 and 9. As understood from theabove description, in the case of applying the alternating current, thedirection of the electromagnetic force applied to the molten metal M isswitched between the opposite directions in a short period, and similarstates where the molten metal M is vibrated are obtained as illustratedin FIGS. 20 and 21, and therefore, it is possible to obtain a greatereffect of separating the impurities by the Archimedes electromagneticforce. Note that, in this case, when a weak effect is confirmed inaccumulating the impurities IM at the peripheral portion PP of theproduct P at the time of applying the alternating current, the magneticfield device 2 can be detached or set to the non-operating state,although it depends on an actual device. The reason therefor is asfollows. The N and S directions of the magnetic field generated by thealternating current are changed. On the other hand, an external magneticfield is a static magnetic field. Accordingly, the static magnetic fieldand the external magnetic field cancel each other. Thence, in a case ofapplying the alternating current, it is better to exclude the externalmagnetic field. Additionally, in experiments conducted by the presentinventor described later, the direct current is applied in a state ofapplying the magnetic field by the magnetic field device 2.

Next, an embodiment of the present invention using the above-describeddevice 100 will be described. Here, the description will be provided fora case in which the magnetic field device 2 is set to the operatingstate and the direct current is applied.

First, in FIG. 1, the container 1 is detached from the metal productmanufacturing device 100 and made to the state illustrated in FIG. 1A.Next, the upper end plate 6 of the detached container 1 is detached asillustrated in FIG. 8, and a non-ferrous metal or another metal providedwhich is solid, provided as a raw material, and containing impurities isstored inside the container 1. Next, the upper end plate 6 is attachedto the container body 5 in a sealed state. As the raw material, it ispossible to use, for example, the non-ferrous metal or another metalselected from scrap or the like and containing impurities. Additionally,as an amount of the raw material, an amount that allows electricalconduction between a molten metal and the pair of electrodes 8 and 9when the raw material is melted and becomes the molten metal afterwardis selected.

Next, the container 1 is put into a heating furnace (not illustrated)such as an electric furnace, and then heated, and the raw material, inother words, the non-ferrous metal or another metal inside the container1 is melted and made into the molten metal M.

After that, the container 1 is taken out from the melting furnace, andis incorporated into the device 100 as illustrated in FIG. 1.Consequently, the current I can be applied to the molten metal M insidethe container 1 by the pair of electrodes 8 and 9, and a magnetic fieldcan be applied to the molten metal M by the magnetic field device 2.

After that, cooling is performed in a state of applying the directcurrent I in the present metal product manufacturing device 100 like (a)or (b) above, for example.

After the cooling, a product P of the solidified non-ferrous metal oranother metal is taken out from the container 1.

An end surface of the billet-shaped product P thus obtained isillustrated in, for example, FIG. 14. In other words, the product P isobtained as a product containing a large amount of impurities at theperipheral portion PP and containing little impurities in the innerportion IP. After this, the peripheral portion PP of the product P isremoved by a desired means to obtain a final product.

To mass-produce the products P, it is suggested to provide a pluralityof metal product manufacturing devices 100.

Additionally, a device made from electromagnets is used as the magneticfield device 2, switching between the state where the magnetic forcelines ML run from right to left and the state where the magnetic forcelines ML run from left to right as illustrated in FIG. 19 can beperformed by switching magnetic poles at a predetermined period (1 Hz to10 Hz or the like) in FIG. 19. In this case, the direct current is to beapplied as the current I.

Note that, in the embodiment of the present invention described above,the case of obtaining the billet as the product P while using thecylindrical container 1 has been exemplified, but a slab may also beobtained as the product P while using a rectangular cylindricalcontainer 1.

EXAMPLE

Next, an example actually performed by the present inventor will bedescribed.

As the container body 5, a container body made from a mullite tube wasused. As a non-ferrous metal provided as a raw material and containingimpurities, Al-10 mass % Fe having a size of ϕ18 mm×a length 50 mm wasstored inside this container body. For the pair of electrodes 8 and 9,graphite electrodes were used.

This was put into an electric furnace to melt the raw material.

The container 1 containing the molten metal that was melted and had atemperature of about 1000° C. was incorporated into the metal productmanufacturing device 100, and a magnetic field (0.54 T) was applied bythe magnetic field device 2, and then cooling was performed whileapplying, as the current I, direct currents of various values betweenthe pair of electrodes 8 and 9. The values of the current I wereappropriately selected from a range of 20 A to 100 A. Note that voltageto be applied at this time is to be adjusted such that the current comesto have an expected value.

A product P (prototype) thus obtained was verified as follows. That is,an end surface of the obtained product P was roughly polished by a knownmeans, and then buffed. A structure of this end surface was observed bymacroscopic structure observation and structure observation by anoptical microscope. FIGS. 22 to 26 were obtained from color photographsof the macroscopic structure obtained at this time. These FIGS. 22 to 26selectively indicate, from among the impurities, Al3Fe as an impuritythat might cause quality deterioration particularly in aluminum. InFIGS. 22 to 26, values of the applied currents and dimensions of theproducts are additionally indicated, respectively.

As understood from results thereof, the impurities Al₃Fe wassuccessfully accumulated at the peripheral portion PP of the product P.Additionally, it was also found that the impurity Al₃Fe was moresuccessfully accumulated at the peripheral portion PP when the currentof 100 A or less was applied under the conditions of the presentexperiment described above. Having studied this, it is estimated thatwhen the current was large, the electromagnetic force F11, F21, F12, andF22 was too strong, and Al₃Fe was dispersed inside the base. Judgingfrom this, it can be considered that there are optimal values for:strength of the magnetic field of the magnetic field device 2; andmagnitude of the current. Such optimal values depend on variousparameters, such as a kind of the non-ferrous metal or another metal asthe raw material (a kind of a molten metal), various dimensions, atemperature, magnetic field strength, a current value, and other values.Note that, according to the inventions previously proposed by thepresent inventor (Japanese Patent Nos. 5,669,504 and 5,431,438), it wasnot possible to obtain a product in which impurities were accumulated ata periphery. The reason therefor might be that a molten metal is morestrongly stirred, and the impurities that are likely to be gathered atthe periphery by the Archimedes electromagnetic force are distributedinside the molten metal. Note that, as understood from theabove-described example, current density is set to, preferably, about 10to 40 A/cm². Accordingly, a current amount to be applied is to bechanged in accordance with a diameter of the product P.

1. A metal product manufacturing device including a container thatstores a molten metal having a conductive property, the metal productmanufacturing device comprising: a cylindrical container body portion;an upper end plate and a lower end plate configured to close both endsof the container body portion in a sealed state; an upper electrodefixed to the upper end plate in a state of passing through the upper endplate, and having an inner end electrically connectable to the moltenmetal; and a lower electrode fixed to the lower end plate in a state ofpassing through the lower end plate, and having an inner endelectrically connectable to the molten metal, wherein at least the upperend plate is detachable from the container body portion, the upperelectrode is fixed to a substantially central portion of the upper endplate in the state of passing through the upper end plate in a thicknessdirection, the lower electrode is fixed to a substantially centralportion of the lower end plate in the state of passing through the lowerend plate in a thickness direction, and the upper electrode and thelower electrode are located on a substantially vertical straight line inan upper-lower direction.
 2. The metal product manufacturing deviceaccording to claim 1, wherein the upper electrode and the lowerelectrode are detachable from the upper end plate and the lower endplate, respectively.
 3. The metal product manufacturing device accordingto claim 1, wherein a power supply device capable of applying a directcurrent or an alternating current is connectable to and disconnectablefrom the upper electrode and the lower electrode.
 4. The metal productmanufacturing device according to claim 1, further comprising a magneticfield device, wherein the magnetic field device includes a pair ofmagnet bodies located outside the container and arranged at positionsfacing each other interposing the container, and an N pole of one magnetbody and an S pole of the another magnet body face each other via thecontainer.
 5. A metal product manufacturing method of manufacturing ametal product from a molten metal having a conductive property, themetal product manufacturing method comprising: preparing a containerthat includes: a cylindrical container body portion; an upper end plateand a lower end plate configured to close both ends of the containerbody portion in a sealed state; an upper electrode fixed to the upperend plate in a state of passing through the upper end plate, and havingan inner end electrically connectable to the molten metal; and a lowerelectrode fixed to the lower end plate in a state of passing through thelower end plate, and having an inner end electrically connectable to themolten metal, wherein at least the upper end plate is detachable fromthe container body portion, the upper electrode is fixed to asubstantially central portion of the upper end plate in the state ofpassing through the upper end plate in a thickness direction, the lowerelectrode is fixed to a substantially central portion of the lower endplate in the state of passing through the lower end plate in a thicknessdirection, and the upper electrode and the lower electrode are locatedon a straight line in an upper-lower direction; making the metal havingthe conductive property and stored inside the container into a state ofa molten metal while the container is sealed by the upper end plate andthe lower end plate; electrically connecting the inner ends of the pairof electrodes to the molten metal having the conductive property; andapplying a current between the pair of electrodes in this state.
 6. Themetal product manufacturing method according to claim 5, comprisingapplying a direct current or an alternating current between the pair ofelectrodes.
 7. The metal product manufacturing method according to claim6, comprising applying an alternating current of 1 Hz to 10 Hz as thealternating current.
 8. The metal product manufacturing method accordingto claim 5, further comprising: preparing a magnetic field device, inwhich the magnetic field device includes a pair of magnet bodies locatedoutside the container and arranged at positions facing each otherinterposing the container, and an N pole of one magnet body and an Spole of the another magnet body face each other via the container;applying, to a molten metal contained inside the container, a magneticfield directed in one lateral direction by the one magnet body and theanother magnet body; and applying a current between the pair ofelectrodes in this state.
 9. The metal product manufacturing methodaccording to claim 8, wherein a device including a permanent magnet isused as the magnetic field device.
 10. The metal product manufacturingmethod according to claim 8, wherein a device including an electromagnetis used as the magnetic field device, and polarities of the pair ofmagnet bodies are switched within a range of 1 Hz to 10 Hz.
 11. Themetal product manufacturing method according to claim 5, wherein acurrent of 60 A to 100 A is applied as the current.